The present invention relates to hemming sheets of metal material. More specifically, the present invention relates to a method and apparatus for forming hems in sheets of metal material.
A hem is formed in a sheet of metal when one edge thereof is bent over onto itself. Further, it is typical that a second sheet is secured within this bend or hem. To form a hem an edge of the metal sheet is bent at angle of about 120.degree.. This initial bend may be accomplished with any well known hemming die, for example, Accurate Brake Die Div. part numbers 130-131, 134-135 or 132-133; Verson pan nubmers V-483 and V-484; or RK part numbers H-1 through H-6. The bent edge of the metal sheet is then bent over (i.e., approaching an angle of 180.degree.) onto the sheet by a press or other similar device, as is well known in the art. If the hem is to include a second sheet secured within the hem, the second sheet is disposed in the bend prior to the final bend with the press. When the edge is first bent to an obtuse angle a dangerous situation is often created. The press causes the sheet of metal (often held by hand) to snap up, which may result in injury to the operator.